It has been a challenge to distinguish between seismic anomalies caused by complex lithology and hydrocarbon reservoirs using conventional fluid identification techniques,leading to difficulties in accurately predicti...It has been a challenge to distinguish between seismic anomalies caused by complex lithology and hydrocarbon reservoirs using conventional fluid identification techniques,leading to difficulties in accurately predicting hydrocarbon-bearing properties and determining oil-water contacts in reservoirs.In this study,we built a petrophysical model tailored to the deep-water area of the Baiyun Sag in the eastern South China Sea based on seismic data and explored the feasibility of the tri-parameter direct inversion method in the fluid identification of complex lithology reservoirs,offering a more precise alternative to conventional techniques.Our research found that the fluid modulus can successfully eliminate seismic amplitude anomalies caused by lithological variations.Furthermore,the seismic databased direct inversion for fluid modulus can remove the cumulative errors caused by indirect inversion and the influence of porosity.We discovered that traditional methods using seismic amplitude anomalies were ineffective in detecting fluids,determining gas-water contacts,or delineating high-quality reservoirs.However,the fluid factor Kf,derived from solid-liquid decoupling,proved to be sensitive to the identification of hydrocarbon-bearing properties,distinguishing between high-quality and poor-quality gas zones.Our findings confirm the value of the fluid modulus in fluid identification and demonstrate that the tri-parameter direct inversion method can significantly enhance hydrocarbon exploration in deep-water areas,reducing associated risks.展开更多
Analysis of 3 D seismic data and well log data from the Rovuma Basin in East Africa reveals the presence of a late Eocene channel-lobe complex on its slope.The first two channels,denoted as channel-1 and channel-2,are...Analysis of 3 D seismic data and well log data from the Rovuma Basin in East Africa reveals the presence of a late Eocene channel-lobe complex on its slope.The first two channels,denoted as channel-1 and channel-2,are initiated within a topographic low on the slope but come to a premature end when they are blocked by a topographic high in the northwest region of the basin.New channels migrate southeastward from channel-1 to channel-6 due to the region’s sufficient sediment supply and stripping caused by bottom currents.The primary factors controlling the development of the channel complex include its initial paleo-topographic of seafloor,the property of gravity flows,the direction of the bottom current,and the stacking and expansion of its levees.The transition zone from channel to lobe can also be clearly identified from seismic sections by its pond-shaped structure.At a certain point,thest systems record a transiton from erosive features to sedimentary features,and record a transition from a confined environment to an open environment.Channels and lobes can be differentiated by their morphologies:thick slump-debris flows are partly developed under channel sand sheets,whereas these slump-debris flows are not very well developed in lobes.Well log responses also record different characteristics between channels and lobes.The interpreted shale volume throughout the main channel records a box-shaped curve,thereby implying that confined channel complexes record high energy currents and abundant sand supply,whereas the interpreted shale volume throughout the lobe records an upward-fining shape curve,thereby indicating the presence of a reduced-energy current in a relatively open environment.Within the Rovuma Basin of East Africa,the average width of the Rovuma shelf is less than 10 km,the width of the slope is only approximately 40 km,and the slope gradient is 2°–4°.Due to this steep slope gradient,the sand-rich top sheet within the channel also likely contributes to the straight feature of the channel system.It is currently unclear whether the bottom current has any effect on its sinuosity.展开更多
BACKGROUND The occurrence of long-term bilioenteric anastomotic stenosis can readily induce liver atrophy and hyperplasia,thereby causing significant alterations in the anatomical and morphological aspects of the live...BACKGROUND The occurrence of long-term bilioenteric anastomotic stenosis can readily induce liver atrophy and hyperplasia,thereby causing significant alterations in the anatomical and morphological aspects of the liver.This condition significantly hampers the accuracy of preoperative imaging diagnosis,while also exacerbating the complexity of surgical procedures and the likelihood of complications.CASE SUMMARY A 60-year-old female patient was admitted to the hospital presenting with recurring epigastric pain accompanied by a high fever.The patient had a history of cholecystectomy,although the surgical records were not accessible.Based on preoperative imaging and laboratory examination,the initial diagnosis indicated the presence of intrahepatic calculi,abnormal right liver morphology,and acute cholangitis.However,during the surgical procedure,it was observed that both the left and right liver lobes exhibited evident atrophy and thinness.Additionally,there was a noticeable increase in the volume of the hepatic caudate lobe,and the original bilioenteric anastomosis was narrowed.The anastomosis underwent enlargement subsequent to hepatectomy.As a consequence of the presence of remaining stones in the caudate lobe,the second stage was effectively executed utilizing ultrasound-guided percutaneous transhepatic catheter drainage.Following the puncture,three days elapsed before the drain tip inadvertently perforated the liver,leading to the development of biliary panperitonitis,subsequently followed by pulmonary infection.The patient and her family strongly refused operation,and she died.CONCLUSION The hepatic atrophy-hypertrophy complex induces notable alterations in the anatomical structure,thereby posing a substantial challenge in terms of imaging diagnosis and surgical procedures.Additionally,the long-term presence of hepatic fibrosis changes heightens the likelihood of complications arising from puncture procedures.展开更多
文摘It has been a challenge to distinguish between seismic anomalies caused by complex lithology and hydrocarbon reservoirs using conventional fluid identification techniques,leading to difficulties in accurately predicting hydrocarbon-bearing properties and determining oil-water contacts in reservoirs.In this study,we built a petrophysical model tailored to the deep-water area of the Baiyun Sag in the eastern South China Sea based on seismic data and explored the feasibility of the tri-parameter direct inversion method in the fluid identification of complex lithology reservoirs,offering a more precise alternative to conventional techniques.Our research found that the fluid modulus can successfully eliminate seismic amplitude anomalies caused by lithological variations.Furthermore,the seismic databased direct inversion for fluid modulus can remove the cumulative errors caused by indirect inversion and the influence of porosity.We discovered that traditional methods using seismic amplitude anomalies were ineffective in detecting fluids,determining gas-water contacts,or delineating high-quality reservoirs.However,the fluid factor Kf,derived from solid-liquid decoupling,proved to be sensitive to the identification of hydrocarbon-bearing properties,distinguishing between high-quality and poor-quality gas zones.Our findings confirm the value of the fluid modulus in fluid identification and demonstrate that the tri-parameter direct inversion method can significantly enhance hydrocarbon exploration in deep-water areas,reducing associated risks.
基金The China-ASEAN Maritime Cooperation Fund Project under contract No.12120100500017001the National Natural Science Foundation of China under contract Nos 42076219,92055211 and 42006067
文摘Analysis of 3 D seismic data and well log data from the Rovuma Basin in East Africa reveals the presence of a late Eocene channel-lobe complex on its slope.The first two channels,denoted as channel-1 and channel-2,are initiated within a topographic low on the slope but come to a premature end when they are blocked by a topographic high in the northwest region of the basin.New channels migrate southeastward from channel-1 to channel-6 due to the region’s sufficient sediment supply and stripping caused by bottom currents.The primary factors controlling the development of the channel complex include its initial paleo-topographic of seafloor,the property of gravity flows,the direction of the bottom current,and the stacking and expansion of its levees.The transition zone from channel to lobe can also be clearly identified from seismic sections by its pond-shaped structure.At a certain point,thest systems record a transiton from erosive features to sedimentary features,and record a transition from a confined environment to an open environment.Channels and lobes can be differentiated by their morphologies:thick slump-debris flows are partly developed under channel sand sheets,whereas these slump-debris flows are not very well developed in lobes.Well log responses also record different characteristics between channels and lobes.The interpreted shale volume throughout the main channel records a box-shaped curve,thereby implying that confined channel complexes record high energy currents and abundant sand supply,whereas the interpreted shale volume throughout the lobe records an upward-fining shape curve,thereby indicating the presence of a reduced-energy current in a relatively open environment.Within the Rovuma Basin of East Africa,the average width of the Rovuma shelf is less than 10 km,the width of the slope is only approximately 40 km,and the slope gradient is 2°–4°.Due to this steep slope gradient,the sand-rich top sheet within the channel also likely contributes to the straight feature of the channel system.It is currently unclear whether the bottom current has any effect on its sinuosity.
文摘BACKGROUND The occurrence of long-term bilioenteric anastomotic stenosis can readily induce liver atrophy and hyperplasia,thereby causing significant alterations in the anatomical and morphological aspects of the liver.This condition significantly hampers the accuracy of preoperative imaging diagnosis,while also exacerbating the complexity of surgical procedures and the likelihood of complications.CASE SUMMARY A 60-year-old female patient was admitted to the hospital presenting with recurring epigastric pain accompanied by a high fever.The patient had a history of cholecystectomy,although the surgical records were not accessible.Based on preoperative imaging and laboratory examination,the initial diagnosis indicated the presence of intrahepatic calculi,abnormal right liver morphology,and acute cholangitis.However,during the surgical procedure,it was observed that both the left and right liver lobes exhibited evident atrophy and thinness.Additionally,there was a noticeable increase in the volume of the hepatic caudate lobe,and the original bilioenteric anastomosis was narrowed.The anastomosis underwent enlargement subsequent to hepatectomy.As a consequence of the presence of remaining stones in the caudate lobe,the second stage was effectively executed utilizing ultrasound-guided percutaneous transhepatic catheter drainage.Following the puncture,three days elapsed before the drain tip inadvertently perforated the liver,leading to the development of biliary panperitonitis,subsequently followed by pulmonary infection.The patient and her family strongly refused operation,and she died.CONCLUSION The hepatic atrophy-hypertrophy complex induces notable alterations in the anatomical structure,thereby posing a substantial challenge in terms of imaging diagnosis and surgical procedures.Additionally,the long-term presence of hepatic fibrosis changes heightens the likelihood of complications arising from puncture procedures.
